US1266882A - Process of manufacturing cane-sugar. - Google Patents

Description

N. M. THOMAS & C. G. PETREE. PROCESS OF MANUFACTURING CANE-SUGAR.

APPLICATION FILED JAN. I4. I918.

Patented May 21, 1918.

NEEEMIAH-MORTIMER THOMASQ'OF PYMBLE, NEAR SYDNEY,.1\TEW SOUTH WALEStAND I r orrcn.

on'rnnnn'r enonen rn'rnnn, or nt'mnABE'R-G, QUEENSLAND, A'U'STRALIA;

. necneee.

. Specification of Letters Patent.

PROCESS OF MANUFACTURING CANESUGAR.

Application filed January 14, 1918. Serial No. 211,703. i

cane is defecated by the addition of lime and the applicat-ion of heat. In this treatment a heavy precipitate of scum and mud, hereinafter called mind, is produced, and collected by settling-and decantation. lfhe mud is pumped into filter presses and the filtrate is returned to the raw juice oris added to clarified juice drawn from the settling yessels. lln-some' instances the whole of the juice after defecation is passed through filter presses. b

Extraction .of sugar chargeddiquids from defecation mud by filter pressing or by treating it in centrifugal machines is subject to the disadvantage that costly apparatus involving considerable labor cost forits operation is necessary. g It has been proposed to extract the sugar charged liquid from the mud returning themud. to the milling circuit at a point therein subsequent to the initial shredding or,crushing, with the/object that'the sugar charged liquid it contains will be expressed by subsequent crushing'and its solid elements retained in. the megass. his not ultimately profitable to return to the milling circuit the defecation mud produced from rich juice or from mixed rich and thin'juices obtained respectively in the early stage or stages of the crushing, because the liquid contained in the mud so produced is richer in sugar than is the liquid content of the macerated megass which enters the rolls at the stage of crushing following next after theapplication of the mud to the megass.

-- A satisfactory efliciency of extraction of a sugar from the cane is attainable only when w the megass in process of crushing is subjected to progressive ,maceration and for-this purposethe sugar content in the expressible liquids must progressively diminish. The

a. usual method when more than two stages of crushing areemployed is to return thethin 'juicefrom the final. stage or sta es of the crushmg to the megass after it eaves the Patented may at; ota.

early stage or stages of the crushing and to apply maceration water to the megass prior to the final stage or stages.

Our invention has for its object to provide a means whereby the sugar charged liquid may be extracted from the defecation mud by distributing such mud on the meg-ass in the milling circuit. without the addition of plant which is costly to operate, and without the disadvantage of requiring increase in the volume of maceratlon water-otherwise necessary for reducing the residual sugar in the final megass to a practical minimum, and without detriment to the -eficiency of the extraction of sugar from the cane.

Our intention consists in distributing upon the 'megass in the milling circuit a specially prepared defecation mud. This special preparation of the mud is effected by mixing mud produced from defecation of rich juice with raw'thin juice obtained in a later stage or stages of multiplecrushing and submitting the mixture to defecation and settling thence withoutincreasing the quantity of maceration water otherwise necessary. obtaining a mud the liquid element of which is less rich in sugar: than is the liquid content of the macerated mega whlch enters the rolls at the stage of crushing following next after the said distribution of such mud 011 the inegass.

We may proceed in either of two ways,

, whichare identical in principle and object.

In the first case we add the mud produced from defecation of the rich juic (5. e., the natural juice obtained in the first stage or stages of the crushing) to the raw thin juice obtained in a later stage or stages of crushing, and we mix the clarified juice from the thin juice defecation with the rich juice, before the latter is defecated, taking the clarified juice from the defecation of the mixture of rich juice and clarified thin juice direct to the evaporating plant. After the process is established in operation this mud obtained from the defecation of so-called rich juice isin. fact mud obtained from the defecation of a mixture of raw rich u ce and the previously defecated clarified thin uice. In the the clarified thin juice with the raw ric juicefand instead thereof carry the clarified second case we'may omit the step of mixin thin juice direct I to the evaporating plant separately or'in conjunction with the clarified rich juice. In either case the sugar content in'the liquid element of the mud isreduced below the sugar content in the liquid contained in the macerated first megass entering the second mill, so that it can be safely introduced into the milling circuit after the first crushing. I

The process will suffer appropriate adaptation in each case, having regard to the mill plant in which it is-installed, accordingto current princ ples of sugar mlll operation. In a three mill crushing plant, for instance, the specially prepared defecation mud and't-he rawjuice from the third mill, separately or admixed, would be applied to i the megass after it'leavesthe first mill, and i the megass "after leaving the second mill- ,would be macerated with Water. Our first method is diagrammatically illustrated for a threemill crushing plant in Figure 1 of theaccompanying drawing; and

V our modified method-for a similar plant is tling vessel H. The clarified juice from the settling vessel H passes to the evaporating plant by the pipe line J and the mud'pa'ssesx ,by the pipe line or-launder K to the tank goes by the pipe line Q to the ta which receives the screened thin juice from the mill B, via the screen M. The mud and the thin juice are limed and'transferred. by the pump N fromtheta-nk L to the heater 0 and thence to the settling vessel Pf The clarified juice from-the settlin vessel P .E, where it mixes with the rich juice and the mixture is defecated. iT-he mud from 'the settling vessel P goes by the pipe line or launder R, to the megass between the mill A and the mill B. Maceration water is applied to' the megass between the mill B and the mill 0, and

, the thin juice from the mill .0 may be applied either with the mud fromithe settling vessel P, or separately, to the megass. .In Fig. 2 the only difference from the process above described is .that the clarified juice from the settling vessel P goes .dlrect to the evaporating plant by the pipe line S, instead of' being brought to the tank E.

Obviously the introduction into the milling circuit of mud containing in its liquid element a higher percentage of sugar than is carried by the liquid in the macerated me-.

gass entering the rolls at the stage of crushing following such introduction .of mud militates against the successful operation of the milling process, and either increases the quantity of the sugar lost in the final megass or renders necessary the addition of an otherwise unnecessary. quantity of water to reduce to a reasonable margin of loss the quantity of sugar which remains in the final megass, thereby entailing additional cost for evaporating the su'peradded water.

It is not practicable to add the defecation mud to the shredded cane befolcthe first crushing, as the shredded cane is at that stage heavily charged with juice and is not capable of absorbing any substantial quantity of additional liquid or of effectively retaining the solid elements of the mud.

What we claim as our invention and desire to secure by Letters Patent is I 1. In a process for extracting sugar cane juice by successively crushing and macerating sugar cane, defecating the extracted products, and returning the defecation mud to the milling circuit, producing a specially prepared defecation mud for the said purpose by first mixing thin juice with mud obtained from defecation of richer juice and defecating the mixture whereby a mud is produced the liquid element of which is lower in sugar content than is the liquid element in the macerated megass with which such mud is incorporated and crushed. 2. In a process for extracting sugar cane juice. by successively crushing and macerating sugar. cane, defecating the extracted substances and returning the defecation mud to themilling circuit, reducing the sugar content of the liquid element in the defecation mud below the sugarcontent of the liquid element in the macerated megass which enters the rolls at the stage of crushing'fo lowingnext after the point in the milljuice by successively crushing and macerating sugar cane, wherein defecation mud is returned to the milling circuit for the extraction of sugar charged liquid therefrom and for the retention of the solid elements of said mud with the megass, mixing mud obtained from defecation of relatively rich juice or juices extracted in the first stage V ing-circuit at which said mud is returned to or stages of'the crushing, with raw thin juice extracted in the later stage or stages of the crushing and defecating this mixture of mud and raw thin juice-to procure thereby a final min the liquid element of which is lower in sugar content than is the liquid element of the macerated megass which enters the rolls at the stage of crushing following next after the point in the milling circuit at which said mud'is returned to'said circuit. v

sists in submitting the cane 'to a succession of crushings with intermediate maceration of the megass, defecating and settling the thin juice obtained in the late stage orstages of thecrushing, admixing the clarified juice from said thin juice with. rich juice obtained in the early stage or stages of the crushin defecating such mixed juice separately rom said thin juice, admixing the defecation mud from the said mixed juice which is rich in sugar content with said thin juice prior to defecation of said thin juice and distributing the mud which is obtained from the defecation of such mixture of mud and thin juice upon the megass at a point in the milling circuit where the liquid element of said mud is lower in sugar content megass which enters the rolls at the stage' than is the liquid element of the macerated of crushin following next after the point in the-milling circuit at which said mud is distributed on the megass.

5.111 a process for extracting'sugar canejuice by successively crushing and macerat-.

mg sugar cane, and defecating the extracted stage of crushin products and returning the defecation mud to the milling circuit, reducing the sugar content of the liquid element of the mud prior to returning it to the milling circuit below the sugar content of the liquid element of the megass which enters the rolls at the point in the mil 'ng circuit at which said mud is returned by reducing the sugar confollowing next after the i tent of'the raw rich juice by admixing clari- -fied thin juice therewith,.thus reducin the sugar content of the defecation mu ob- .tained from said rich juice and admixing ate'd mud and raw .thin juicefor the production of said clarified thin juice and of a still further attenuated mud for returns ing to the milling circuit, 7

6. The herein described improvement in the extraction of sugar cane juice, which consists in crushing the cane in a plurality ofstages with intermediate maceration of the megass, defecating the rich juice obtained in the early stage or stages of the crushing, passing the clarified rich juice to the factory and mixing the rich mud therefrom witi raw thin juice obtained in the late stage or stages of the crushing, defecating the mixture of rich mud and raw thin juice, passing the clarified thinjuice to the evaporating plant and distributing the mud therefrom upon the megass at a point in the milling circuit where the liquid element of the mud is less rich in sugar than is the liquid content of the macerated megass which enters the rolls at the stage of crushing following next after the said distribution of mud upon the megass. 7 In'testimony whereof we have signed our names to this specification in the'presence of two subscribing witnesses.

. NEHEMIAH MORTIMER THUMAS.

CUTHBERT GEORGE PETBEE.

Witnesses:

W. J. DAVIS, HEATHER PETER.

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